We selected all the TOIs orbiting Solar-type stars, for which there are not yet available time-series or precision radial velocities observations. We found 375 TOIs and performed their probabilistic validation analysis using the VESPA code
We statistically validated 61 TESS candidates orbiting Solar-type stars
We corrected their radius for stellar dilution: 4 of them could be of stellar nature
We analyzed their stellar neighbourhood to find possible contaminating stars: 11 of them do not have possible contaminants, while the others need further investigation starting from On-Off photometry to confirm the source of the transit signal
To select the candidates orbiting Solar-type stars, we built an intrinsic color-magnitude diagram in the Gaia band, correcting the photometry for distance modulus, extinction and reddening. We calculated the former using the parameters from the Bailer-Jones catalog (Bailer-Jones et al. 2018), while we used the Stilism software (Capitanio et al. 2017) to evaluate the extinction. We obtained the V-band extinction for all the stars and then converted it into the Gaia photometric bands with specific conversion factors.
From the color-magnitude diagram, it is possible to extrapolate all the stars belonging to a certain spectral class. We could do this using the Mamajek's table (Pecaut & Mamajek 2013), which provides average color and magnitudes parameters for each spectral class and therefore allows a selection based on them. We selected stars from F9V to G8V spectral classes, took into consideration only Planet Candidates (PC) not under investigation by the TESS team and excluded each TOI for which time-series or Precision Radial Velocity (PRV) observations were already available. In total, after discarding single-transit candidates, 375 TOIs survive within our selection.
Here we presented our ongoing follow-up program of TESS candidates orbiting Solar-type stars without any kind of time-series or precision radial velocity observations available. Our probabilistic validation analysis allows to identify which are the most promising candidates and the evaluation of their stellar neighbourhood determines which is the next follow-up observation needed to confirm the exoplanet candidate. The final goal of the entire procedure is to avoid losing observational time at expensive facilities and optimize follow-up resources. In particular, we statistically validated 61 TESS candidates orbiting Solar-type stars. Eleven of them have been confirmed to orbit their host star and can be prepared for the radial velocity observations, while the others need photometric observations.
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